Amazing charge speed!

The potential drawbacks aren't worth the benefits to a low range PHEV in the US. DC fast charging does put more strain on the battery, potentially shortening its life.

 

DC fast-charging doesn't work reliably with the current lithium-ion battery technology, significantly reducing the cycle life due to lithium-metal plating on the anode's surface, as slow diffusion in the carbon anode can't keep up with transferring the lithium ions to the inside of the carbon lattice. Lithium-metal batteries (in which lithium-metal plating on the anode is how the battery works) or high-silicon-content-anode batteries (in which lithium-metal plating is reduced because silicon anode allows faster lithium-ion diffusion, reducing the piling of lithium metal on the anode's surface) are needed for reliable DC fast-charging, which are currently under development.

 

I was under the impression that the model sold in Japan supported fast charging, am I correct in that assumption?

 

It is, but it is known that extensive use of fast charging can lead to reduced life for the battery is terms of capacity loss. With the current Li-ion chemistry in most plug ins, there are strategies to reduce this loss. A big one is to greatly reduce the charge rate when the pack reaches 80% charge. The last 20% is around the speed of a Level 2. This is why such charge times are quoted for reaching 20%. Another is to keep the pack cool. Either by the pack cooling system, or by slowing the charge rate.

This all hinders a Prius Prime's ability to fast charge. A smaller pack could shed heat at a faster, but for the same amount of electricity over a given time, the smaller pack heats up faster. This is because as energy is 'pushed' into a cell, the cell 'pushes' back with increasing internal resistance. Smaller pack means less cells. On top of that, the PP has just air cooling with a fan moving air through the pack. This isn't best way to do things.

Then a smaller pack reaches 80% faster, which is the point, but the steps taken to protect the battery means it is slower than bigger batteries. The PP takes 20 minutes to reach 80%, which is about 20 miles of range. In the same amount of take, a Leaf, with one of the worse battery cooling systems used, could add about 50 miles.

On a trip, you'll end up spending more time at chargers staying to EV only than with a BEV, or even a PHEV with a bigger battery. When getting a charge while on an errand, a DC charger will get the battery almost full. Or use a cheaper Level 2, get less miles charged, but avoid the extra strain on the pack, and maybe use a little gasoline in one of the most efficient ICE cars available.

Then why does the Prius PHV have CHAdeMO in Japan? Well, to be blunt, Japan's residential grid sucks. The service to many homes means a PP will take over 10 hrs to fully charge from flat, and home Level 2 isn't possible. Then the cost of energy is higher there, though electricity from a pay charger likely beats out gasoline. So the cost to the battery for fast charging has a different balance that makes it more acceptable.

Japan also has power stations available for home chargers that are vehicle to home. So plug ins, and FCEVs, there can be used as home generators. These stations work through a CHAdeMO plug. Even the PiP had CHAdeMO for this.

 

I would not use DC fast-charging on any current EV. It is detrimental to the battery cycle life with the existing lithium-ion battery technology. If you are in a real hurry—OK, use it once or twice, but keep in mind that you're taking a huge chunk out of your battery's cycle life.

 

So, that means all of today's BEVs should be used for commuter drive solely on home charges but not for a long trip requiring DC fast charging on the road? I wonder what the Tesla Supercharger users would think about that restriction.

 

The risk is only with batteries that see frequent fast charging. Smaller packs are just at a higher risk because of their size could magnify the charge conditions that are harmful.

I'm saying the PP has an ICE on board. Use it instead to avoid those risks.

Or those Prius Prime drivers using charge mode. That is fast DC charging.

 

Here is some data on what DC fast-charging does to the Tesla 2170 battery. At 4C (15-minute) charging, it lasts for only about 20–30 cycles. If you used it regularly, you wouldn't get more than about a 6,000-mile life on the battery.

https://www.quantumscape.com/resources/blog/white-paper-a-deep-dive-into-quantumscapes-fast-charging-performance/

 

Well, if that is the case, then new Vinfast BEVs which will be sold without the traction battery in the sales price, and the owner has to lease the battery pack and pay a monthly fee is starting to look really good for those who do long-distance trips regularly. As for me, it is of no concern. Not a single DC fast charge station within 250 miles (in the US side)... I could go to the Canadian side but... why would I?

 

Then it is a good thing Tesla doesn't charge their cells that fast, and that they have an effective cooling system for the pack.

Now, what EVs will be using Quantumscape batteries?

Don't put strain on EV batteries when there isn't a need to do so, but also don't let the perfect be the enemy of good enough.

Except for fringe use cases, EV batteries will be fine with occasional DC charging.

Even a PP would be fine with it, otherwise there wouldn't be a charge mode. The issue is that it is easier to reach that fringe use is easier to reach with a small battery with air cooling.

Then people say they want fast DC charging in a PP, but are they willing to pay for it. When it was an option on the Bolt, the price was $700 or more. Prius Prime starts at a far lower price. The extra equipment isn't expensive, but it isn't free.

 

This point can NEVER be overstated (and that applies to EVERYTHING, not just EVs).

If not, there’s not much point in thinking of a BEV as an only car for well over half of all North Americans.